In order to operate a storage system in an optimum and safe manner, it is required to analyze a state of the storage system and perform necessary configuration modifications. With regard to the storage system analysis, for example, Patent Citation 1 describes retrieving and detecting a server group from mapping information between a storage device and a server and narrowing down to only the performance data of the server group to facilitate identification of a server group causing the contention of I/O or a portion acting as a performance bottleneck on a resource in a storage device and preparing a report on I/O contention. Patent Citation 2 describes that a storage administrator monitors performance of a storage device to prevent a performance problem from occurring, as a mechanism of monitoring performance of a storage system.    Patent Citation 1: Japanese Patent Application Laid-Open Publication No. 2005-062941.    Patent Citation 2: Japanese Patent Application Laid-Open Publication No. 2007-233783.